This invention relates to a method of measuring the quality of a resistance weld, typically the welded joint which forms the side seam of a metallic can.
Applicant' earlier patents EP 0381312B and EP 0438204B are directed to techniques for monitoring resistance welds in metallic cans, for example by measuring the relative movement of the electrode wheels of the resistance welding apparatus. The present invention provides a further method of measuring the quality of resistance welds, which is capable of generating additional information concerning the welding process.